Electromagnetic switch.



J. D. IHLDBR.

ELEGTROMAGNETIO SWITOH.

APPLIOATIOK nun 00w. 11,1907.

936,724. Patented 0ct.12,1909. 3 SHEETS-SHEET 1. F191.

1 7 voi a wows; W C/w J. D. IHLDER.

ELEOTROMAGNETIG SWITOH.

APPLICATION FILED OUT. 11,1907.

Patntefl 0ct.12,1909.

a sums-sum 2.

J. D. IHLDER.

ELECTROMAGNETIC SWITGH. APPLICATION FILED OCT. 11,1907.

Patented Oct. 12, 1909.

311 \mwioz f UNITED STATES PATENT OFFICE.

JOHN D. IHLDER, OF NEW YORK, N. Y., ASSIGNOR TO OTIS ELEVATOR COMPANY,OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELECTROMAGNETIC SWITCH.

Specification of Letters Patent.

Patented Oct. 12, 1909.

Application filed October 11, 1907. Serial No. 396,980.

To all whom it may concern:

Be it known that I, JOHN D. IHLDER, residing in New York, in the countyof New York and State of New York, have invented a new and usefulImprovement in Electromagnetic Switches, of which the following is aspecification.

My invention relates to electro-magnetic switch mechanism, and certainfeatures of the invention are especially adapted to mechanism of thiskind in which a plurality of switch arms are operated successively by anelectro-magnet or magnets to close a series of electric circuits.Switches of this character are used for various purposes, a well knownexample of such use being found in accelerating magnets for electricmotors, in which an electro-magnet operates a plurality of switchessuccessively to gradually shortcircuit the starting resistance of themotor. In multiple magnet switches of this kind the operation of theswitch arms in their proper order is obtained in various ways, as, forexample, by adjusting their armatures to diiferent distances from themagnet when in open position, or by weighting the arms to differentdegrees. But no special means is provided to insure that the switch armsshall open in the reverse order.

One of the objects of the present invention is to provide positive meansfor insuring the closing of the switch arms in the proper order, andalso to prevent them from being opened out of their proper order. In thecase of an accelerating magnet it is necessary that the switch arms beoperated in their proper order to obtain a gradual cutting out and in ofthe starting resistance, and to avoid the arcing which occurs when theswitches are opened out of order.

A further object of the invention is to provide improved means to permitthe switch arms and also the stationary contact-carrying arms to bereadily removed and replaced.

With this object in view, an important feature of the invention residesin means for pivotally and removably supporting the switch arms.

Another feature of the invention resides in the means for locking thestationary cont-actcarrying arms in position.

Other objects of the invention will appear more fully hereinafter, andthe novel combinations of elements will be pointed out in the claims.

Referring to the drawin s, Figure 1 is a front elevation of a multipleswitch electromagnet to which my invention is applied; Fig. 2 is a sideelevation of the same; Fig. 3 is a front elevation of a single switchelectromagnet; Fig. 4 is a detail view of the looking pin for thestationary contact arms; Figs. 5 and 6 are views of the ivot bolts forthe switch arms of the multiple switch and single switch magnets,respectively; Fig. 7 shows a locking arm for the pivot bolt; Fig. 8 is aplan view of a support in which the stationary contacts are mounted; andFig. 9 is a view of one of said contacts.

Figs. 1 and 2 show a multiple switch electro-magnet in which apluralityof switch arms are operated by a single magnet. The magnet framecomprises a vertical bracket 1 of magnetic material secured to avertical base or support 4 by means of bolts 2. A horizontally disposedmagnet core 3 is also secured to the face of the bracket 1 by means ofthe bolts 2 which pass through the support 4 and bracket 1 and into themagnet core, the openings in the bracket and core being screw-threadedto receive the threaded ends of the bolts. The magnet winding consistsof a single coil 5 wound in the usual way on a spool 6, elongated to fitthe core 3. Arms 7 integral with and extending horizontally forward fromthe bracket 1 are provided at their forward ends with circular openingsto receive a rod 8 on which are pivoted the switch arms a, b, c, d.These switch arms are made of magnetic material and extend upwardly infront of the magnet core 3 in position to be operated thereby. Eachswitch arm has an integral lug 9 formed thereon which is provided with athreaded opening to receive an adjustable screw bolt 10. The heads ofthe bolts rest on a horizontal bar 11 when the switch arms are open andlimit the outward movement of the arms. The stop bolts 10 are locked intheir adjusted positions by lock nuts 12. These stops 10 are adjusted sothat each switch arm, commencing with the arm a, is somewhat nearer itsarmature than the next arm to the left. As

' and having a result of this arrangement when the magnet is energizedby a gradually increasing current in the winding 5, the switch arm awill be first'moved, and then the arms b, 0 and d in re lar order.

The articular means for pivotally and remova ly mounting the switch armsforms an important feature of this invention and is as follows. Thelower end of each switch arm is widened and bifurcated to form two arms13, 14 with a slot 15 between them. This slot is narrower than thediameter of the bearing rod 8 except at its upper end where it isenlarged and curved to an arc of a circle, and forms a bearing surfaceto receive the rod 8. The rod 8 (see Fig. '5) is circular incross-section except the portions of its length which form bearings forthe switch arms. These portions each have a segment cut away to form afiat surface 16 which reduces the .diameter of the rod to somewhat lessthan the width of the slot 15. With this construction, all that isnecessary to be done in removing a switch arm is to turn the rod 7 tobring the flat surface 16 in line with the slot 15, when the switch armmay be lifted right off. When the bearing rod 8 is turned to extend theflat surface 16 across the slot 15 the switch arm is locked againstremoval. I

The bearing shaft 8 is locked in position by means of a lock arm 17(Fig. 7). This lock arm which is made of spring brass or other resilientmaterial, is rovided at one end with a segmental openlng 18 to fit onthe end of the shaft 8 which projects slightly beyond the arm 7. Thelock arm is secured in position on the shaft by a cotter pin 19. Nearits outer end the lock arm is formed with lugs 20 bent inwardly at rightangles to the body of the arm. These lugs are adapted to straddle thearm 7 of the magnet frame, and lock the bearing shaft 8 with its flatsurfaces 16 extending across the slots 15. When it is desired to removea switch arm from its bearing rod 8, the free end of the lock arm 17 issprung out to release the lugs 20 and then turned down, rotating theshaft 8 until the flat faces 16 are in line with the slots 15 when anyswitch arm can be removed by simply lifting it off the rod 8. Thisconstruction provides for the quick removal of any switch arm withoutremoving the rod which carries it, and without the removal of split orcotter pins or other devices as heretofore in use. This construction bymeans of which the arms are quickly interchangeable is useful where asingle switch arm is used, but especially so where a number of arms aremounted on a single rod.

Each switch arm carries at its upper end a contact 22 made of copper orother metal a rod or stem 23 extending through the switch arm. Thecontact 22 and its stem 23 are insulated from the switch arm by bushings24 of insulating material. Flexible conductors 25 are electricallyconnected to the contact 22 by means of a connector 26 mounted on thestem 23. The parts are clamped in position by a nut27 on the threadedend of the stem 23.

The stationary contacts are mounted in supports S secured to the base 4.Each of these supports S comprises a pair of parallel arms A (Fig. 8)extending forward from the base 4, and a vertically arranged solid bodyportion B formed in one piece with the arms A and extending below saidarms. The inner ends of the arms A are united by a transverse member 30which abuts against the base 4. A rod or stem 31 extends from the part30 through the base 4 and is screwthreaded to receive a' clamping nut.The body portion B has three openings 33, 34, 35 extending therethrough,in which are yieldingly mounted the stationary contacts 36, 37, 38,arranged in vertical alincment in position to be engaged by the contact22 on the switch arm. The middle and lower contacts are preferably madeof copper and each formed with a stem consisting of short section 39(Fig. 9) of large diameter and a longer section 40 of smaller diameter.The section 40 which is preferably circular in cross-section hassegments cut away near its outer end to form a neck 41. The openings 34,35 each comprises a section in which slides the enlarged end of thecontact stem, and a smaller section to receive the part 40 of thecontact stem. .Coil springs 43 43 are placed in the openings 41 behindthe enlarged sections 39 of the contact stems. The upper contact 36which is made of carbon and extends farther forward than the other. inorder to take up the arcing when the switch is opened, is held in aclamp 44 con sisting of upper and lower members united by a screw bolt45. The clamp 44 has a stem similar to those of the copper contactsexcept that the enlarged portion 35) and the neck 41 are longer topermit a greater range of movement of the carbon contact, the enlargedportion of the opening 33 also being made deeper for this purpose.

The contacts are secured against removal from the support S by a key K(Fig. 4). This key which is preferably made of sheet brass or othersheet metal, has a portion cut away to form a longitudinal slot 47between parallel arms 46. The slot 47 is formed with arc-shapedenlargements 48 at distances corresponding to the distances be tween thecontact stems. The end of the key is bent at right angles to the body toform a handle 49. The key is slidably held in the support S by lugs 50formed on the body portion B and arranged opposite the contact stems.Vhen in locking position the arms 46 of the key straddle the necks 41.of the contact stems with the enlarged portions 48 of the key slot belowtheir respective contact stems. The slot 47 is just wide enough topermit a free longitudinal movement of the contact stems limited inextent by the length of the necks 41. When it is desired to remove acontact, the key is raised far enough to bring the enlarged portions 48of the slot opposite the contact stems, when any contact may be removed.Or, the key may be lifted entirely out of the holder if desired. The keyK not only looks the contacts against removal, but forms a stop to limittheir movement in both directions. Flexible conductors 52 extend fromeach contact to binding posts 53, insuring good electrical connectionbetween the contacts and their support S.

To insure the opening and closing of the s\-vitch-arms in their properorder, the arms 0, c and d are provided with lateral extensions 55 whichproject into the path of the arms a, b, 0, respectively. Theseprojections may be either rigid and cast integral with the switch arm,or in the form of a spring. W hen the switch arms are closed, eachprojcction 55 bears against the adjacent arm, so

that each arm is held in attracted position by those to the right of it,leaving only the arm (.6 free. l V hen the arm (Z opens it frees the arm0, which may then open and free the arm Z), and so on throughout theseries, so that no arm can open out of its turn. In closing the arms,the reverse order takes place, as the arms I), c and d are each heldopen until the arms a, b, and 0, respectively have closed. The sameresults could be obtained with other arrangements of the stops 55.Various other arrangements might be adopted to secure the same result.

If the projections 55 are in the form of springs they may each be undera moderate tension when the switch arms are closed. Each projection 55will then tend to open its switch arm a certain distance before thesucceeding arm is free to open. For example, the spring projection 55 onthe arm d will exert a yielding pressure on the arm 0. This pressurewill react to open the arm d somewhat earlier and quicker than it wouldopen otherwise, and at the same time yieldingly hold the arm 0 closeduntil the arm d has opened far enough to remove the spring 25 from thearm 0. The switch arms therefore will not be opened so nearlysimultaneously as when rigid projections are used.

Fig. 3 shows a modification in which my improved form of pivotalconnection for the switch arms is applied to an electro-magnet having asingle switch arm. The pivot bolt 8 (see Fig. 6) has a central circularbearing portion journaled in the arm 7 of the magnet frame, and endportions with flattened surfaces 16 to form bearings for the bearingportions 14 of the switch arm. The construction and operation is similarto that described in connection with the n'mltiple switch magnet.

Although I have shown and described my invention as applied to anaccelerating magnet in which a plurality of switch arms are operated bya single n'iagnet, it is obvious that. it might also be applied to aconstruction in which each switch arm is operated by a separate magnet.The invention is applied to any series of parallel switch arms that aredesigned to be operated successively, whether by a single magnet orseparate magnets or whether used to control a motor starting resistance,or for some other purpose. Further, I wish not to be limited to detailsof construction and arrangement of parts shown, as various changes inthese might be made without departing from the spirit and scope of theinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is 1. In an electro-magnetic switch mechanism, the combinationwith an electro-magnet, switch arms, and stationary contacts, of acombined lock and pivot shaft for the switch arms, and a locking key forthe stationary contacts substantially as described.

2. In an electro-magnetic switch mechanism, the combination with anelectro-magnet, switch arms, and stationary contacts, of a combined lockand pivot shaft for the switch arms, a locking key for the stationarycontacts, and means for preventing the operation of the switch arms outof a predetermined order.

3. In an electro-magnetic switch mechanism, the combination with amagnet, of a pivot shaft rotatably mounted on the magnet frame, aplurality of switch arms mounted on the shaft and removable therefromwhen the shaft is rotated to certain positions, contacts carried by theswitch arms, stationary contacts carried by the magnet frame, a key forlocking the stationary contacts against removal, and means forpreventing the operation of the switch arms out of a predeterminedorder.

4. In an electro-magnetic switch mechanism, the combination With amagnet and a plurality of switch arms, of a shaft on which said arms aremounted, a plurality of stationary contacts, a locking key therefor,said shaft and key being movable into positions to either lock orrelease the switch arms and stationary contacts, respectively, and meansfor preventing the operation of said arms out of a predetermined order.

5. In an electro-magnetic switch mechanism, the combination With amagnet, of a pivot shaft, a plurality of switch arms pivoted on theshaft and removable therefrom in a direction perpendicular to the shaftwhen the shaft and arms are in certain relative positions, but lockedagainst removal when in other positions, means for limiting the pivotalmovement of the arms, means for securing the shaft in position to lockthe arms against removal throughout their range of pivotal moven-ient,and means for preventing the operation of the arms out of apredetermined order when thus locked.

(5. In an electro-magnetic switch mechans ism. the combination with amagnet, 21 plurality of pivoted switch arms, and a plurality ofstationary contacts, of means for locking the stationary contactsagainst removal, means for locking the switch arms against removal, andmeans for locking the switch arms against operation out of a pre- 15determined order.

In testimony. whereof, I have signed my name to this specification inthe presence of two subscribing witnesses.

JOHN D. IHLDER.

'r. w. A. GoLnyr

